So far it's a fine performance by the young Dutchman and top seed Anish Giri, who is the solo leader of the Qatar Masters Open with 4/4. Thus far he hasn't been tested, and today he crushed his opponent, Mikhailo Oleksienko, in just 18 moves on the white side of a Caro-Kann - and he was probably winning after Black's 10th move. (In case you're wondering, Oleksienko is a GM with a 2620 rating; this isn't some sort of master vs. amateur rout at the local club!) Ouch.
Five players are just half a point behind - Evgeny Tomashevsky, Nils Grandelius, Yuriy Kryvoruchko, Shakhriyar Mamedyarov, and Pavel Eljanov - and then there are a ton of players with 3/4, including Vladimir Kramnik. Kramnik started with two draws and a very shaky win in round 3, but in round 4 he finally looked more like himself and is getting back into the hunt. The top American player so far, Sam Shankland, also has 3 points, and several Americans have 2.5 points including Daniel Naroditsky, Alex Lenderman and Irina Krush. (Krush had an especially impressive victory in round 3 over Sergey Fedorchuk, and with the black pieces at that.) Another notable 2.5 pointer is Bela Khotenashvili. She defeated Baadur Jobava in round 1, and today in round 4 she defeated another super-strong GM, Gabriel Sargissian.
It's a very strong tournament, and as you can see from the foregoing even top GMs aren't getting much "respect" from their opponents. Especially notable among the super-GM victims are Arkadij Naiditsch, whose 2719 rating still left him with an 0-2 start, and after a win in round 3 he lost to an IM in round 4 to fall to 1-3. Even worse: Viktor Bologan started 0-3 and only managed his first draw of the event today, against an FM. (Worse yet: while some might conceivably have a tough time in Qatar because they're unused to the climate, I believe Bologan has spent a lot of time working as a trainer there over the years. He's just having a very bad tournament.)
Five rounds remain.